Phase determination for colemanite, CaBO3O4(OH)3.H2O

Abstract

The procedures used to calculate the signs of the structure factors for colemanite, a P21/a crystal, are described in some detail. The F2obs. are adjusted for vibrational motion and put on an absolute scale. From the corrected E~kl, the magnitudes of the normalized structure factors Ehkz are calculated, and the signs of these determined by the application of the 2:1, 2:2, and 27s formulas of Monograph I of Hauptman & Karle (1953).

The Crystal Structure of Levoglucosan Triacetate

“…No absorption correction was applied in the data reduction procedure. Normalized structure factors were generated by the K-curve method (9).…”

A method for the extension and refinement of crystallographic protein phases utilizing the fast Fourier transform

“…This high resolution case, for myoglobin and vitamin B-12, has been considered by Hoppe & Gassmanrt (1964) with a reciprocal space convolution of F's. From a set of about 9000 2A myoglobin intensities, we first computed the normalized structure factors Eobs, using the K-curve method of Karle, Hauptman & Christ (1958). The origin term, E(0,0,0), was calculated on the basis of the 2400 myoglobin atoms in the unit cell, thus effectively ignoring the solvent contribution to the intensities.…”

The crystal and molecular structure of pyridoxal phosphate oxime

“…Normalized structure factors (E values) were computed by the K curve method (Karle, Hauptman & Christ, 1958) which establishes scale and temperature corrections for the observed structure factors. Table 1 shows the experimental values for several functions of the normalized structure factors compared with the corresponding theoretical values for centrosymmetric and non-centrosymmetric structures respectively.…”